Sewing machine



NowZl, 1950 N. v. CHRISTENSEN ETAL 2953v860 SEWING MACHINE '7 Sheets-Sheet l Filed sept. 4, 1946 NOV 21 1950 N. v. CHRISTENSEN ETAL. 2,539,860

SEWING MACHINE Filed Sept. 4, 1946 7 Sheets-Sheet 2 l5 INVENTORS. NORMAN.V.CHR\3TENSEN BY CHARLES. F. RU BEL Nov. 2l, 1950 N. v. cHRlsTENsEN ETAL 2,530,860

SEWING MACHINE Filed sept. 4, 194e 7 sheets-sheet s FIG 4 l 1 I 64 I ;rv..` JIJ.

J 7o @9* o l 7s l f7 ff" --V- 66 f 52 l l I '|:r V 56 $4-, 'I 45 I 13 19 18 /L f f J INVENTORS. NORMAN CHNSTENSEN CHARLES. F. RU BEL ATTORNEY NOV- 21, 195@ N. v. cHRlsTENsx-:N ETAL $30,663

SEWING MACHINE Filed Sept. 4, 1946 '7 Sheets-Sheet 4 INVENTORS. 168 NDRMANV, CHR\STENSEN BY CHARLESF. RUBEL TTRZ N. v. cHRlsTENsEN Erm. l 2,530,860

SEWING MACHINE Nov. 2l, 1950 '7 Sheets-Sheel'l 6 Filed sept. 4, 194e A j w 3 INVENToRs. NoRMANA/.cHmsTleNsEN BY CHARLES. F. RUBEL Nov. Z1, 1950 N. v. cHRlsTENsl-:N Erm. 2,530,860

SEWING MACHINE Filed Sept. 4, 1946 7 Shee'cs-Shee'l 7 s 42 l .l F G Z Q lunumwlullt llllll INVENTORS. NORMANVCHNSTENSEN BY CHARLES .F RUEEL ITTOR/VE Patented Nov. 2l, 1950 SEWING MACHINE Norman V. Christensen and Charles F. Rubel,

Chicago, Ill., assignors to Union Special Machine Company, Chicago, Ill., a corporation of Illinois Application September 4, 1946, Serial No. 694,688

The present invention relates to improvements in sewing machines, and more particularly to an improved system for lubricating the hook raceway of a high speed lockstitch machine.

It is a principal object of the invention to provide in a machine of this description, a novel and improved lubricating system which is well adapted to insure a continuous, positively controlled, even flow of lubricant to the raceway associated with a high speed rotary hook. Specically, it is an object of the invention to insure adequate lubrication of the raceway at all times while at the same time precluding any possibility of an excess which might result in spattering of the lubricant and in the soiling of the work.

lIt is a further object of the invention to provide for use in a machine of the class described, having a rotary hook and a hollow hook actuating shaft mounted to turn on a horizontal axis, a novel means rendered operative by the rotation of the shaft for drawing lubricant from a reservoir through lubricant feed connections which include a lubricant flow restriction, whereby a more positive, continuous, and readily controlled flow of lubricant through the lubricant feed connec" tions to the raceway is maintained at all times during machine operation.

It is a further object of the invention to pro- 6 Claims. (Cl. 112-256) frs vide for the introduction of an occasional booster i filled, and to insure that lubricant is continuously supplied to the raceway.

In high speed lockstitch machines of the general class here described, and more particularly in lockstitch machines having a rotary hook supported to turn on a horizontal axis, difficulty has been experienced in providing an adequate and satisfactory system of lubrication for the hook raceway which will insure proper lubrication for all conditions of operation in which the machine may be intermittently started and stopped, or may be maintained in continuous operation for a relatively extended period. 4

In accordance with the invention, it is proposed to employ a system of lubricant feed connections to the raceway, including a conduit which extends along the axis of rotation of the actuating shaft for the hook, and which is constructed and arranged to provide means which is rendered operative by rotation of the shaft for drawing lubricant from the reservoir through an adjustable lubricant flow restriction and through said conduit to supply lubricant to the raceway continuously and in exactly controlled amounts.

In the preferred form of the invention herein illustrated, the actuating shaft for the rotary hook is formed with an axial bore along its length, and the conduit thus provided is given a helical form by means of a coiled square section spring member which is assembled with a core rod within the bore, and has a friction engaging nt with the wall of the bore to turn as a unit therewith. The helical passageway provided by the spring member extends through the bore in the direction of now of lubricant of opposite hand from the direction of rotation of the actuating shaft and hook driven thereby.

Another feature of the invention consists in the provision of means which is rendered operative only on occasion to force a substantial charge of lubricant past the lubricant flow restriction to the lubricant feed connections for the raceway, so that any possibility of failure of adequate lubrication of the raceway as a result of an inadequate supply of lubricant within said connections is avoided. In the illustrated form of the invention, an auxiliary lubricant pumping device is provided comprising a piston which is actuated by the upward and downward movement of the presser foot lifting connections to supply a charge of lubricant to the lubricant feed connections each time the machine is stopped and then started. Further in accordance with the invention, this mechanism is readily available to permit the operator to force an additional charge of lubricant to the hook raceway at any time t during machine operation as, for example, to

overcome any observed tendency of the hook mechanism to overheat.

Another feature of the invention consists in the provision of a device which may be employed by the operator to flush the lubricant feed connections to the raceway, and thus to remove any dirt or other obstruction which may have found its way into lubricated portions of the hook assembly Without the necessity of taking down the machine. The mechanism provided in accordance with the invention to this end, comprises a by-pass valve which may be opened by the operator when the machine is running idle to cause lubricant in relatively large amounts to be driven through the lubricant feed connections to the raceway.

Another feature of the invention consists in an improved construction and arrangement of a needle valve which is adapted to provide an accurately adjustable restricted fiow of lubricant from the reservoir through the feed connections to the raceway.

With the above and other objects in view as may hereinafter appear, the several features of the invention consist also in the devices, combinations, and arrangements of parts hereinafter described and claim-ed, which ltogether with the advantages to be obtained thereby will be readily understood by one skilled in the art from the following description taken in connection with the accompanying drawings, in which Fig. l is a view in front elevation of a lockstitch machine embodying the invention, portions -Uf the casing having been broken fawayiand sectioned to show underlying parts; iFig. '2 'is an :enlarged detail View of the needle head in front elevation, the casing and portions of fthe thread Vtake-up having been broken away and sectioned in order to illustrate particularly the driving 'connections for the reciprocating needle and rotary take- -up; Fig. :3 Vis fan enlarged detail .view, in iront elevation, of 'the :rotary' hook andthe rotatable hook actuating shaft, `these-beingsectioned to'il-' lustrate vparticularly a Aportion of 'the lubricant vfeed 'connections tothe bobbin 'carrier supportfingraceway; Fig. 4 vis a View in fieft side veleva-- tionof the machine, :withthe cover -pl'ate for rthe rneedle head removed and-with the base :broken Yaway and sectioned to 4show funderlying parts; Fig. 5 is a verticalsectional viewtaken through the needle head on'aiplane rearwardly tof .the .plane of 'Fig 2 to 'illustrate particularly the presser foot controlmec'hanism; Fig. `6 is asectional view on an enlarged scale taken on the line 6 8 of Fig. 'B to illustrate Aparticularly the .ar- 'rangement of the lubricant Treservoir for Athe 4hook'raceway in .the base; 'Fig..7iis;a View in-.right side 'elevation of the machine, With'a-portionnf lthe :casing broken away tand sectioned :to illus- Ntrate 'particularly Vthe ,connections for actuating the Zhook *raceway lubricant pump from 'the ypresser foot lifting mechanism; Fig.`8 is a :horizontal sectional view `takenthrough"the'machinie 'base to illustrate particularly the arrangement 4of 'the devicesfor supplying lubricant to the driv- "ing connections, and particularly 'to the `hook raceway; Fig. '9 is 'a 'detail 'section'alview on an enlarged scale taken along'the axis of the hook shaft; Fig. 10 is an enlarged'detail sectiona'iview taken on the line IS-IBof Fig. v8; and Figs 11, y12, and 13, are detail views'illustrating *analn ternative form and arrangement of `needle valve which may form part of 'the'hook raceway'lubrieating system of the present invention, Fig. "1'1 being a vertical sectional 'view illustrating particularly the disposition -of the hook lubricant reservoir with relation totherotaryhook actuating shaft in the base,`-Fig.'12being a `horizontal section on an enlarged scale with portions `of the base sectioned to illustrate the relation of the main actuating shaft -to the yhook lubricant reservoir, and Fig. '13 being a 'further enlarged vertical sectional view looking from the right of Fig l2, showing particularly themodified form yci needle valve.

The lockstitch sewing machine illustrated in y fThe thread handling mechanism of theimachine fin a sleeve 56.

includes also a rotary take-up consisting of a rotary cam plate iii and a thread engaging element i l mounted in an eccentric location on the plate. The work supporting and guiding devices of the machine include the usual cloth plate I8, a presser foot I9 and a feed dog 2D which is adapted to engage and to feed the work against the yielding supporting surface provided by the under face of the presser foot I9.

The invention has been illustrated in connection with a lockstitch sewing machine of the type shown and described in the Christensen and 4Rubel -Patent No. 2,113,572, granted April 12, 1938. This machine comprises a main frame havinga .baseportion 2! providing a work supporting surface, and a vertical standard 22 from .the upper end of which extends laterally an overhanging arm 2li. Power is supplied to the Inachine through a combined hand wheel and pulley 26 secured to the outer end of a shaft 28 -Whichis vmounted atene end in a bearing (not shown) .in the outer wall of the vertical standard .2-2 andfat-an lintermediate point and at its other end in bearings Sil-.and 32 Acarried by the over- Yhanging arm. The shaft 28 extends substantially thefulllength of the overhanging arm into -adreedle'head 34 atthe free end ofthe arm. The `connections for driving the several devices in -the'base ofthermachine includera gear 35 mount- .ed *on shaft .23, an idler gear v38 on a stub shaft di@ vin the standard 22, and-a gear =4I which-is secured on a-drive shaft 42 (see Figs. 1 and:8) which extends along the ylengthvof the base 4vfor :driving the krctary hook and work feed devices ofthema'chine.

The needle I3 of the illustrated machine 'and needle :bar 4G to which the needle is attached,

-are .reciprocated in the .conventional manner lby .means 'of a'crank is secured to the forward end :of the-drive'shaft -28 (see Figs. 2 and4) and a .link 53 connected at its'other lend to a 'collar'52 fast on the needle bar'd.

The presser foot I9 issupported ina conventional manner on the lower end of a presser `bar 513 which `is supported for axial movement A compression Aspring 6G coiled about the bar between a collarfZ on the bar and an upper bearing member 64 tends to hold the presser foot yieldingly against the work'or the throat plate. The presser foot is arranged to be Yraisedby means of a collar "66 which is slidably .mounted on the presser bar and normally rests .on the upper end of the sleeve v56.

The collar 66 may be lifted through connections which include a vertically extending actuating link E8 adapted for operation by a treadle, a lever 'i9 `(see Figs. '4, Y5, and 7), a rock shaft 'I2 extending along the length of the overhanging arm, an arm 'M secured to the shaft 'i2 Within the needle head, and a link 'I6 pivotally secured at its lower end to the collar G6 on the presser bar 56. At its upper end the link/I5 has an elongated slot 18 connected with a laterally extending pin 'i9 on the arm 14. A torsion spring 8E! .coiled about the rock shaft I2 (seeFig.5) tends to rock the shaft in a clockwise direction as viewed in Fig. 4,

to maintain the :presser foot lifting connections in a normally 'inoperative position as there shown.

The thread take-up provided with the present machine, comprising the-cam disk IE andthread vrengaging'element I'! on the disk above referred to, are mounted to rotate on a take-up shaft 84 which is supported in parallel relation t'o the main drive shaft 28 and is driven therefrom by intermeshing gears 86, 88.

The 'mechanisms actuated from the drive shaft 42 in the base include the rotary hook I5 which is mounted on a hollow hook actuating shaft 90 which has its right end journalled in a bushing 92 pressed into a downwardly depending casting wall 94 in the base (see Figs. 8 and 9), and is further supported adjacent its forward end in a bearing formed in the casting wall 98 of the base. The actuating shaft 90 and hook I5 supported thereon are driven from shaft 42 by intermeshing gears 98, at the rate of two revolutions of the hook I for each comlete reciprocation of the needle I3. The rotary hook assembly including the relatively stationary bobbin carrier I4 and the rotary hook l5 may be of well known construction, the bobbin carrier I 4 being provided on its external periphery with a flange I 82 which is mounted to turn in a raceway |04 formed' in the hook member I5 (see Fig. 3)

The feed dog I9 of the illustrated construction, has imparted thereto horizontal and vertical reciprocatory movements to engage and to feed the work against the support provided by the bottom surface of the presser foot I9. This mechanism is driven from the drive shaft 42 in the base through connections which in the illustrated machine are similarV to those disclosed in the patent to George Sauer et al. No. 2,035,- 568, granted March 31, 1936. These connections as shown in Fig. 4, include a feed bar It on which the feed dog 2s is carried and afeed rocker |08 to which oscillatory motion is imparted through connections from the `drive shaft 42. Inasmuch as this mechanism is fully illustrated in the Aabove noted patent to Sauer, et al. and forms no part of the present invention, further illustration and description thereof is omitted.

The lubrication system provided for lubricating the rotary hook raceway which forms more specifically the subject matter of the present invention, comprises a raceway lubricant reservoir IIll which is formed in the base in align-- ment with the hollow hook actuating shaft 99. Lubricant is drawn from the reservoir through a helical conduit provided as hereinafter more fully set forth in an axial`bore I I2 in the actuating shaft 98 and delivered into a chamber II4 formed by the internal diameter of the sleeve hub of the rotary hook I5, thence outwardly through a radial duct i IE in the hook member I5 and transversely through an extension I IB thereof to the raceway |534. As best shown in Fig. 3, the chamber I I4 is closed by means of a circular disk |22 having formed therein a small hole |22 which serves to prevent any possibility of an air lock forming in the connections.

As best shown in Figs. l., 5, and 8 of the drawings, the hook lubricant reservoir I IQ is separated from the main reservoir generally designated at III by means of the end-wall 94, an interior side wall H3 and an end wall IIE forming part of the casting, and a bottom plate I Il. The level of lubricant in the main reservoir I I I is conveniently indicated by means of a Lucite gauge I I9, the level in the hook raceway reservoir being similarly indicated by means of a Lucite gauge IZI. A fill plug |23 provides means of access forreillling the hook raceway reservoir IIII, and an additional screw plug |25 provides means of access to the operator for adjustment of the adjustable lubricant flow restriction and the flushing device for the lubricant feed connections to the hook raceway hereinafter to be described.

In'accordance with the invention, novel means is provided which is rendered operative by the rotational movement of the hook actuating shaft to draw lubricant from the reservoir IIB throughY lubricant feed connections including the axial bore II2, radial duct III:` and extension I I8 to the hook raceway |04. The mechanism referred to, comprises a core rod or shaft |24 and a'square section spring member |255, which are assembled within the bore |I2 so that the spring |26 is held in firm fricticnal engagement with the walll of the bore II2 to turn as a unit with the shaft 98. The coil spring |28 acts as a helical vane which extends in the direction of lubricant flow of opposite hand from the direction of rotation of the rotary hook actuating shaft 90.` In accordance with the usual construction, the hook rotates in a counterclockwise direction as viewed from the front of the hook in Fig. 4. In the illustrated construction, the spring I 26 has a lead of about four turns to the inch, and provides a helical passageway of substantial size through the bore.

Further in accordance with the invention, an adjustable lubricant flow restriction is provided in the lubricant connections from the reservoir to the raceway, which operates in connection with the means for drawing lubricant through the connections above described, to provide for a sure and accurate control of the ow of lubricant to the raceway. In the form of the invention illustrated in Figs. 8 and 9 of therdrawings, there is fitted to the rear end Yof the bushing 92, a sleeve member |38 which has formed therein a longitudinal axial bore |32 and a vertically extending radial bore I 34 to receive a needle valve member |353` screw-threaded therein. The needle valve member I 35 is provided with anenlarged head portion having the edge thereof serrated for engagement with a spring detent member |38 which serves to maintain the needle valve in its adjusted position. t

In accordance with another feature of the invention, means are provided which may be readily employed by the operator to clean out the lubricant feed connections without the necessity of changing the oil control adjustment or of disassembling the rotary hook and the associated parts. The mechanism provided for this purpose, comprises a conical valve member |42 having an actuating stem which extends upwardly through a vertical bore in the sleeve member |38, and is y arranged for engagement with a' conical seat |44 in the sleeve member |58. A spring arm |46 held by a machine screw |48 to the under side of the sleeve member |32 engages against the valve member |42 to maintain the flushing valve normally in its closed position. In the event that it is desired to clean out the lubricant feed connections. the operator needs only to press downwardly on the pin |42 while the machine is running idle to cause a relatively large amount of lubricant to be drawn through the axial bore I2 in the actuating shaft QZ! into the chamber H4 whence it is forced outwardly through the radial duct I I6 and its extension I8 to thoroughly clean these parts. f

A further feature of the invention consists in the provision of an auxiliary device for lubricating the hook raceway, which is rendered opp erative occasionally and more particularly whenever the machine is started, to force a charge of lubricant through the lubricant feed connections, and ,thus to supplement the operation of the means above described rendered operative by the 7j, rotation; of the? actuating shaft 96' for continuously drawing 'lubricant from; the supplyv through the lubricant feediconnections; Theauxiliary device referred to for lubricating theY hook raceway, asbest shown in Figs. 1, 4, 8, 9, and 10, comprises a piston pumpV and'check valve arrangementl which is connectedztobe actuated from the presser foot lifting mechanism, and which acts each time thepresser footis raised and thereafter lowered, to force a single charge of lubricant past the needle valve |36 intothebore I |2 in the actuating shaft- 96; The pumpcomp'rises a vertically arranged cylindrical' pump casing |56 in which is supported a piston |52 which is connested at its upper end bysmeans of an actuating link with a laterally extending arm |56 on the presser footY rock shaft 12. Upward movement of the piston |52 causes lubricant to be drawn intol a chamber |66 within the cylindrical member |52A around a ball check valve generally indicated at |62" through an opening in a plug |63 at thebottom of theschamber. The subsequent downward movement of the piston |52 causes the lubricant to be discharged fromY the chamber l'transversely throughV a fitting |66 which carries a ball check Valve |64, through a pipe connection |68t0V the sleevemember 133,' whence it flows through the boreY |32, passing around the stem of needle valve |36, and into the bore |42 in the actuating shaft' 9U. construction and arrangement of they pumping device i'in which the piston |52 is raisedand lowered eachtime the presser foot lifting rod 68 is actuated to raise and then lower the presser foot as van* incidentV to stopping and starting the ma- I chine,V anypossibility of failure of the lubrication system which might result from an insufficient amount of lubricant in the helical passageway providedbyY the spring member |26, particularly upon starting the machine after a relatively long idle period; is avoided. This construction provides also means which is readily7 available to the operator to'further lubricate theraceway whenever'necessary, as in the event that there is any tendency of` the hook assembly to becomeover'- heated. This can be done while the machine is running and-the presser foot remains in its'operating position. For example, the'- presser bar lifting treadle may be operated repeatedly through'a short stroke which is just sufficient to take-up the slack between the collars 62 and 66. r it may be done merely by moving the manual control link 68 upwardly from the position shown in Fig. d, and then down one or more times as maybe desired. To enable this the connection from the rod to the treadle may include a rock member 69 (Fig. 8) whichhas an elongated slot cooperating with a bent overportion'of therod 6d; The oppositearm of member 69 may beconnested directly by a rod with a treadle.

Figs. ll, 12, and 13` of theA drawings, illustrate an alternativeA form and arrangement of needle valve which is particularly adapted to-insure an even new of lubricant through the restriction provided by the-needle valve. A particular advantage of this arrangement is thatit isreadily available for adjustment by the operator from the front of the machine. As shown in these figures, the hollow actuating shaft 96 is journalled in a bearing sleeve |1| carriedby the fra-me and at its inner end extends'intora bushing |12 which is closed by a plug |13 to form an inletchamber to the bore in shaft 90. It will be understoodv that the shaft 90- carries a spring member, like` |26, to' providea helical vimpeller With this thereink Anopening |1l|1in the side of thetbushing |12 registers with a transverse'borey |16 in the end wall |18 of the hook oil'reservoir |10. This" end wall, asshown in Fig. 12, is'recessed to providea small L-shaped extension of the reservoir which communicates with thezbore |16 at its outer end and also at an intermediate point through a vertical bore |86. At the opposite side of the recess in wall'4 |18'another bore |8l; is providedin line with the bore |16 and this extends laterally to the front side of the machine, and has supported'therein a needle valve stem |82 which is' screw-threaded at its outerend into an enlarged portion of the bore. The valve stem may be rotated'for' adjustment and is held in adjustedposition by a locking nut |83. This arrangement of the needle Valve as shown in Figs. ll and 13, in addition to the advantage of accessibility for adjustment by the operator, provides also a somewhat improved condition Within the valve to insure the continued flow of lubricant past the restriction, and substantially eliminates any danger of complete stoppage of flow at this point.

Certain features of construction of the illustrated machine adapted and arranged for the more eflicient lubrication of moving parts 10- cated in the needle head, form the subject matter of a separate application for Letters Patent about to be filed in the United States Patent Oice, and will therefore be referred' to only briefly. The constructions referred to, as shown in Figs. 2 and 5, include a reservoir |96 within which the gears 86, 68 for driving the rotary take-up are mounted, a sump |62 in the needle head, a return conduit |24 from the sump, and a piston-type pump |66 actuated from the rock shaft 12 by meansof a laterally extending arm |98 arranged for engagement with a pump actuating bell-crank lever 266. The pump |96 is arranged with an inlet check valve 232 and a discharge check valve 264 which operate with each reciprocation ofthe piston |96 to cause the latter to draw in from the sump |22 and to discharge into a small pocket or reservoir 2116, a charge of lubricant. From the pocket 266 the oil is delivered to various parts to be lubricated and any excess lubricant is returned to the reservoir |91).Y

While an illustrative form of the invention has been described in considerable detail, it will be understood that numerous changes in the construction and arrangement of the several parts and in the general application of the invention may be made, without departing from its principles and scope. The terms and expressions vused herein have been employed as terms of description and not of limitation.

What is claimed is:

1. In a lockstitch machine, a rotary hook having a bobbin carrier receiving raceway, a rotary hook actuating shaft, a reservoir, lubricant' feed connections from the reservoir to the raceway including a helical conduit extending axially through said shaft in the direction of lubricant flow of opposite hand to the direction of rotation of the shaft and hook, a lubricant ow restriction through which lubricant is drawn'from the reservoir and impelled through said conduit, and means independently of'said restriction and operable at will under the control of the operator to permit a free flow of sufricient lubricant drawn from the reservoir through said conduit to flush out the latter and saidraceway.

2. In a lockstitch machine, 'arotaryhookhaving a bobbin carrier receiving raceway, a rotary hook actuating shaft, a reservoir, lubricant feed connections from the reservoir to the raceway including a conduit extending axially through the shaft constructedx and arranged to be rendered operative by rotation of the shaft to draw lubricant from the reservoir through the conduit, a radially disposed duct in the hook connecting said conduit with the racetvay, an adjustable lubricant now restriction through which lubricant is drawn from the reservoir and irnpciled through said conduit, and means independent of said restriction and operable at will under the control of the operator to permit a free flow of sucient lubricant drawn from the reservoir through said conduit to flush out the latter and said raceway.

3. In a lockstitch machine, a machine casing containing a reservoir, a rotary hook having a bobbin carrier receiving raceway and arranged to turn on a horizontal axis, a rotatable 'nook actuating shaft having an axial bore extending along the length of the shaft, lubricant feed connections from the reservoir to the racer/aj including a core rod and a helical vane assembled in the bore to turn as a unit with the shaft and providing a helical conduit extending axially of the shaft in the direction of flow of opposite hand from the direction oi rotation ci said shaft, a duct connecting said conduit with the raceway, a needle valve through which lubricant is drawn from the reservoir and impelled through said conduit, a connection arranged to by-pass said needle valve through which lubricant is permitted to be drawn freely from the reservoir and impelled through said conduit, andV a normally,7 closed manually actuated valve in said by-pass ,connection.

4. In a lockstitch machine, a rotary hook having a bobbin vcarrier receiving raceway, a rotatable hook actuating shaft, a reservoir, lubricant feed connections from the reservoir to the raceway including a conduit Within said shaft cxtending along the length thereof, said conduit providing means rendered operative by rotation of the shaft tor drawing lubricant continuously from the reservoir and irnpelling it through connections, a lubricant flow restriction through which said lubricant is dravvn from the reservoir, a lubricant pump apart from said conduit adapted when actuated to force a charge of lubricant through said connections, and a manual device for operating said pump independently of the operation of the machine.

5. In a lockstitch machine, a rotary hook having a bobbin carrier receiving raceway, a horizontally disposed rotatable hook actuating shaft, a reservoir, lubricant iced connections from the reservoir to the raceway including an axial bore through the shaft, a lubricant new restriction between the reservoir and said shaft, means for drawing lubricant from the reservoir through said restriction to the raceway comprising a core rod and a helical vane assembled in xed position in the bore within said actuating shaft to provide a helical conduit exten-:ling along the actuating shaft in the direction of iiow of opposite hand from the direction of rotation of the shaft, and a manually operable lubricant pump separate from said shaft connecting the reservoir with said conduit and arranged when actuated to force a charge of lubricant through said conduit.

5. In a lockstitch machine, a rotary hook having a bobbin carrier receiving racevvay, a rotary hook actuating shaft having a bcre extending therethrough, a reservoir, lubricant feed connections from the reservoir to the racevvay including lubricant impelling means and a conduit extending from said reservoir through the bore of said shaft to the raceway, an adjustable lubricant flow restriction through which lubricant passes in its passage from the reservoir to said raceway, a lubricant iiovv connection arranged to by-pass said iiow restriction and deliver lubricant from said reservoir through said sha-ft bore to the race- Way under the pumping action of said impelling means, and a normally closed manually actuated valve in said by-pass connection.

NORMAN V. CHRISTENSEN. CHARLES F. RU'BEL.

REFERENCES CTED The following references are of record in the le of this patent:

UNTED STATES PATENTS Niunher Name Date 1,081,841 Korytynski Dec. 16, 1913 1,679,199 Baker July 3, 192.8 2,248,598 Myers July 8, 1941 2,323,422 Sauer July 6, 1943 2,329,487 Sauer Sept. 14, 1943 2,383,152 Parry Aug. 21, 1945 2,393,815 Sauer et al Jan. 29, 1945 2,395,653 Attwood Feb. 26, 1946 2,400,212 Sauer May 14, 1946 

